Drive unit for a luminescence display panel

Abstract

In a luminescence display panel employing organic EL elements, at the time of switching of a normal scan mode and a partial scan mode, occurrence of an unpleasant phenomenon such as flicker and the like on a display screen is restrained. When a switching command for changing a scan mode is supplied from a scan mode alteration circuit ( 13 ) to a light emission control section ( 11 ), a control circuit ( 18 ) controls so that a switching operation of a scan mode is executed at the time of scanning start of a first scan line or during scanning of a dummy line set after a final scan line. Thus, in a luminescence display panel ( 1 ) employing organic EL elements, a light emission display by a new scan mode is performed from the first scan line in one frame, and occurrence of an unpleasant phenomenon such as flicker can be restrained.

What is claimed is:  
     
         1 . A drive unit for a luminescence display panel which includes a plurality of drive lines and a plurality of scan lines intersecting each other and a plurality of capacitive light emitting elements connected between the drive lines and the scan lines at a plurality of intersecting positions by the scan lines and the drive lines, 
 The drive unit comprising a light emission control means which can select a normal scan mode in which all effective light emitting elements in the luminescence display panel are repeatedly scanned to control the luminescence thereof and a partial scan mode in which part of the effective light emitting elements in the luminescence display panel are repeatedly scanned to control the luminescence thereof, wherein the light emission control means executes a switching operation for the respective scan modes in synchronism with scanning start of a first scan line in each scan mode.    
     
     
         2 . A drive unit for a luminescence display panel which includes a plurality of drive lines and a plurality of scan lines intersecting each other and a plurality of capacitive light emitting elements connected between the drive lines and the scan lines at a plurality of intersecting positions by the scan lines and the drive lines, 
 The drive unit comprising a light emission control means which can select a normal scan mode in which all effective light emitting elements in the luminescence display panel are repeatedly scanned to control the luminescence thereof and a partial scan mode in which part of the effective light emitting elements in the luminescence display panel are repeatedly scanned to control the luminescence thereof, wherein the light emission control means executes a switching operation for the respective scan modes during scanning of a dummy line set after a final scan line in each scan mode.    
     
     
         3 . The drive unit for the luminescence display panel as claimed in  claim 1  or  2 , wherein the light emission control means is constituted to perform a switching operation from the normal scan mode to the partial scan mode and a switching operation from the partial scan mode to the normal scan mode.  
     
     
         4 . The drive unit for the luminescence display panel as claimed in  claim 1  or  2 , wherein the light emission control means is constituted to perform a switching operation from the partial scan mode to another partial scan mode.  
     
     
         5 . The drive unit for the luminescence display panel as claimed in  claim 1 , wherein the light emission control means is constituted to output a switching command at the time of the scanning start of a first scan line whose light emission should be controlled in the next after receiving a switching command from a scan mode alteration means, so that a scan mode can be switched in synchronism with the output of the switching command.  
     
     
         6 . The drive unit for the luminescence display panel as claimed in  claim 1 , wherein the light emission control means is constituted so as to outputs a switching command in synchronism with a switching command from a scan mode alteration means and is constituted so that a scan mode can be switched at the time of the scanning start of a first scan line whose light emission should be controlled in the next.  
     
     
         7 . The drive unit for the luminescence display panel as claimed in  claim 2 , wherein the light emission control means is constituted to output a switching command at the time of the scanning of the dummy line after receiving a switching command from a scan mode alteration means, so that a scan mode can be switched in synchronism with the switching command.  
     
     
         8 . The drive unit for the luminescence display panel as claimed in  claim 2 , wherein the light emission control means is constituted to output a switching command in synchronism with a switching command from a scan mode alteration means and is constituted so that a scan mode can be switched at the time of the scanning of the dummy line.  
     
     
         9 . The drive unit for the luminescence display panel as claimed in  claim 1  or  2 , wherein the light emission control means is provided with a scan period alteration means for changing the scan period of a scan line in accordance with the number of scan lines in each scan mode.  
     
     
         10 . The drive unit for the luminescence display panel as claimed in  claim 1  or  2 , wherein the light emission control means is provided with a luminance variable means for controlling emission luminance in accordance with the number of scan lines in each scan mode.  
     
     
         11 . The drive unit for the luminescence display panel as claimed in  claim 1  or  2 , wherein the light emission control means is provided with a reset control means for setting a reset period for each end of the scan period of a first scan line, the reset control means executing an operation for making the electrical potentials of all of the plurality of drive lines and the plurality of scan lines the same during the reset period.  
     
     
         12 . The drive unit for the luminescence display panel as claimed in  claim 1  or  2 , wherein the light emitting elements are organic electroluminescence elements.